Discussions

3DR Radios - 433mHz or 915mHz for a ground vehilce?

Posted by Niall Dempsey on July 19, 2012 at 3:53am

I'm considering purchasing a 3DR Radio kit for a ground vehicle, which is the best option in this situation, 433mKz or 915mHz ? My understanding is that the 433mHz is probable the better option.

Also, I noticed that the 915mHz kit comes with an air and ground module where as the 433mHz has 2 air modules. Why is this and how can one of the air modues be converted to a ground module?

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –
Follow

Replies

  • Vernon Barry July 19, 2012 at 4:29am

    The whole air/ground module is the fact that these are modems and communicate on the wire side of the radio via TTL level serial (the same thing Arduino uses natively). The ground modules had an additional FTDI chip to convert the TTL to USB. On the 413mHz radios, they had an interference problem with a lot of USB chipsets and thus dropped the additional FTDI chip based ground module and just ship the air modem (TTL only) and you use your own TTL to USB cable (AKA FTDI cable). Logic applies here that the FTDI chip is now in the USB plug at the computer, some distance from the module and eliminates the noise problem.

  • Vernon Barry July 19, 2012 at 4:24am

    What matters is what country you live in. The 915mHz is legal in the US and the 433mHz is legal in some other countries. That fact is actually covered on the page. Don't operate a radio that is not legal where you live.

    DOCUMENTATION, SET UP AND COUNTRY COMPATIBILITY 

     

    Support for different countries/regions

    It is very important that you find out what the local country or region regulations are on frequency, hopping channels and power levels and configure your 3DR Radios correctly for your local rules.

    Here is some general information to help you get started.

    Region Radio Model Settings Standard
    USA 3DR 900 MIN_FREQ=902000 MAX_FREQ=928000 NUM_CHANNELS=50 FCC 15.247
    Canada 3DR 900 MIN_FREQ=902000 MAX_FREQ=928000 NUM_CHANNELS=50 RSS-210 Annex 8.1
    Australia 3DR 900 MIN_FREQ=915000 MAX_FREQ=928000 NUM_CHANNELS>=20 LIPD-2000 item 52
    Australia 3DR 433 MIN_FREQ=433050 MAX_FREQ=434790 TXPOWER<=14 LIPD-2000 item 17
    Europe (most countries) 3DR 433 MIN_FREQ=434040 MAX_FREQ=434790 TXPOWER<=8 NUM_CHANNELS>=30 ETSI EN300 220 7.2.3
    Europe (most countries) 3DR 433 MIN_FREQ=433050 MAX_FREQ=434790 TXPOWER<=8 DUTY_CYCLE=10 ETSI EN300 220 7.2.3
    United Kingdom 3DR 433 MIN_FREQ=433050 MAX_FREQ=434790 TXPOWER<=8 DUTY_CYCLE=10 IR2030/1/10
    New Zealand 3DR 900 MIN_FREQ=921000 MAX_FREQ=928000 Notice 2007, Schedule 1
    New Zealand 3DR 433 MIN_FREQ=433050 MAX_FREQ=434790 Notice 2007, Schedule 1
    Brazil 3DR 433 MIN_FREQ=433000 MAX_FREQ=435000 TXPOWER<=8 Resolução ANATEL nº506/2008
    Brazil 3DR 900 MIN_FREQ=902000 MAX_FREQ=907500 NUM_CHANNELS>=11 Resolução ANATEL nº506/2008
    Brazil 3DR 900 MIN_FREQ=915000 MAX_FREQ=928000 NUM_CHANNELS>=26 Resolução ANATEL nº506/2008
This reply was deleted.

Activity